It is known to provide exfoliation of skin as a light cosmetic procedure. Such a procedure is used to remove dead cells from the outermost layer or layers of the skin. This provides a means of rejuvenating the skin, clearing pores and minimising lines and other marks found on the surface of skin.
One such procedure used to remove dead cells from the outermost layer or layers of the skin is microdermabrasion. Microdermabrasion uses a mechanical medium for exfoliation to remove dead skin cells from the outermost layer or layers of skin, referred to as the epidermis. Benefits include epidermal thickening and collagen deposition.
Microdermabrasion devices generally comprise two parts: an abrasive material to act on and remove the outermost layer or layers of skin, and a suction means to gently lift up the skin and draw the discarded skin particles away from the operating area.
Microdermabrasion devices work by either particle abrasion or non-particle abrasion. With particle abrasion a high pressure stream of particles, such as aluminium oxide, magnesium oxide, sodium chloride, or sodium bicarbonate particles are directed towards the skin to abrade the skin and remove skin fragments from the upper layer or layers of skin. A vacuum is also produced to remove the abrasive particles and exfoliated skin fragments from the area of the skin. With non-particle abrasion, a roughened surface, such as a diamond grit-embedded surface, is moved over the skin to abrade the skin and remove skin fragments from the upper layer or layers of skin.
The skin has two primary layers—the epidermis and the dermis. The epidermis comprises the outermost layers of the skin. Such layers include the stratum corneum (the outermost layer), the stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale. It has been found that removal of the stratum corneum at least aids the beneficial results of microdermabrasion. Therefore, it is necessary to ensure that a suitable depth of abrasion is applied to the skin. However, it has also been found that if the depth of abrasion exceeds a certain level then irritation of the skin or bleeding may occur.
It is known to attempt to achieve a desired depth of abrasion of the skin by applying a predetermined number of passes of the microdermabrasion device to the skin. However, such a method is inaccurate and does not take into account other variables such as different skin types, location of the skin and condition of the skin.
It is to be noted that US patent application US 2008/0249537 A1 discloses a skin treatment device having an abrasive tip comprising a suction hole through which loosened skin particles are removed. The skin treatment device further comprises a sensor to measure the oiliness of the skin to be treated which measurement is used to control the suction. The skin sensor is disclosed to be separate from the treatment unit and to measure the oiliness of untreated skin.
It is further to be noted that international patent application WO 95/12357 A1 discloses a device for removing the stratum corneum by repeatedly placing an adhesive film on a defined area of the skin. The device according to WO 95/12357 A1 comprises a light source to shine a beam of light onto a used part of the adhesive film in order to allow visual inspection of the attached stratum corneum.
It is further to be noted that WO 2008/13454 A1 discloses a device for increasing the skin's permeability by abrasing the skin. The device of WO 2008/13454 A1 comprises a feedback control mechanism based on two electrodes measuring the conductance of the remaining skin which conductance is supposed to be a measure for skin permeability.
Finally, it is to be noted that US 2006/100567 A1 discloses a device for altering tissue by means of an applicator comprising control means to monitor a physical property of the remaining skin.